SciShow Tangents - Listener Mailbag 2

Episode Date: February 16, 2021

We're cracking open the mailbag once again to answer some dusty old questions you sent us a long time ago! Ew, they're all rotten and goopy... well, we'll answer them anyway, because we care.Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links:Peat bogshttps://www.sciencedirect.com/topics/earth-and-planetary-sciences/peatlandhttps://www.britannica.com/technology/peathttps://www.smithsonianmag.com/science-nature/europe-bog-bodies-reveal-secrets-180962770/https://www.sciencedirect.com/science/article/abs/pii/S0305440320300881?dgcid=rss_sd_allhttps://www.culture24.org.uk/places-to-go/south-west/bristol/art20488Spidershttps://www.livescience.com/24054-why-spiders-have-eight-eyes.htmlhttps://www.nationalgeographic.com/news/2011/6/110603-spiders-spare-legs-webs-science-animals/Laser eye surgeryhttps://www.npr.org/templates/story/story.php?storyId=6249164https://pubmed.ncbi.nlm.nih.gov/22496438/https://www.aao.org/munnerlyn-laser-surgery-center/laser-in-situ-keratomileusis-lasik-3https://my.clevelandclinic.org/health/diseases/8586-corneal-diseasehttps://healthcare.utah.edu/the-scope/shows.php?shows=0_yrklfds0Disease eradicationhttps://asm.org/Articles/2020/March/Disease-Eradication-What-Does-It-Take-to-Wipe-outhttps://www.cdc.gov/smallpox/index.htmlhttps://www.oie.int/en/for-the-media/press-releases/detail/article/eradication-isnt-the-end-of-the-rinderpest-story/#Miner's egghttps://journals.sagepub.com/doi/pdf/10.1177/003591572201501935

Hello and welcome to SciShow Tangents, the lightly competitive science knowledge showcase, but this week it is a completely non-competitive question answering extravaganza and also this week we're a damn skeleton crew over on the virtual science couch we've got our resident science expert sari riley hi sari how are you feeling like a skeleton just ready to hang out with my one friend i'm losing them very quickly yep you. You sure are. And then me, the resident voice of the common people, Sam Schultz is also here and that's it. It's just two of us this time. Yep. And Tuna's here too. And Tuna's great. He laughs at your jokes, even though you can't hear him, you can still see him laughing. Tuna's our hype man. So every week on Tangents, as you know, we ask for your questions about upcoming themes for our Ask the Science Couch segment.

And we get a ton of great ones. But every episode, unfortunately, we can only answer one question. So instead of just letting those perfectly good questions collect virtual dust, we've picked a few to answer today. But before we do that, so we have some semblance of normalcy. Sari, will you tell us what a question is? I don't know. The etymology was not as interesting as other words. It was pretty straightforward because I think since we've had language, we needed the idea

of a question as opposed to a statement. That makes sense. So it was used in the early 13th century, the word question, for a philosophical or theological problem. So only really fancy pants thinkers could have questions. But then in the early 14th century, it became just an utterance meant to elicit an answer or discussion. Well, what were they called before that for normal people? I don't know. What the hell?

There's like another word, query. And I think that might have been the word for normal people. I don't know. What the hell? There's like another word, query. And I think that might've been the word for normal people. So like if you're a philosopher, you have philosophical questions. But if you were like asking a merchant how much an apple costs, you had a query. I like that. It's cute.

But I also like that. I bet philosophers were really mad when we took the word question away from them. Probably, yeah. The rabble have it now. Take that eggheads. Well, yeah. The rab will have it now. Take that eggheads. Well, that's amazing. And the Proto-Indo-European root is quo, K-W-O,

which says it is a stem of relative and interrogative pronouns. So any word with that attached or that sound attached generally was associated with asking for something, I think. What, when, who, where, why, like that all starts with the same sound and then morphed throughout history. But then also things like quantity or quandary or quote

all came from that root, apparently. Hell of a root. Yeah, powerful. And not just for the philosophers, for the people. It's a word of the people. We needed that word. We had questions to ask. We didn't know how to do it.

Also, somebody asked the first question at some point and they were probably like, what the fuck? Instead of meat, it was meat. Okay, well, I think we really helped a lot of people with that. So let's move on to people's questions. At Isabella Carls3 asks, Dear finely honed minds of the science couch, how does decomposition in peat bogs work?

I love the way things get preserved in them for thousands of years. So do you. You are obsessed with peat bogs in my perception of you. I think I have brought up bog butter in conversation an unnatural amount of time. I'm just so thrilled by the idea of dairy products being buried in the muddy ground

and then surviving for thousands of years. Because they're forgotten about, right? Is that what it is? Yeah, I think the intent at one point was like, oh, I'm going to go bury some butter in my backyard. Because I don't have a refrigerator because it doesn't exist yet. Refrigeration doesn't exist, but we have this great natural refrigeration in a peat bog, which is marshy land. So it's a wetland ecosystem, which like it sounds, is flooded some or all of the year. And then peat is just a brownish

material that is partially decomposed leaves and other organic matter. So it's not quite dirt and not quite like crunchy autumn leaves. It's like a slurry mush and it creates really anaerobic conditions. So it protects whatever is below it from the air. Instead of being exposed to the air, whatever is buried within the peat bog doesn't decompose as quickly. And so it basically, in cold climates where also the outside weather was cold, so it's not like hot decomposing stuff. It's cold decomposing stuff. It's like a backyard refrigerator. You dig it up and then you're like,

I'm going to put some butter there or I'm going to put this man I just killed there. Except you shouldn't put him there. He'll never go away. Yeah, I think people stored butter there with the intent of preserving them and they stored corpses there with the intent of just like throwing them away

in land that people didn't like walking in. Peat bogs don't happen anywhere, right? Are they in specific places? They're in specific places. A lot of the ones that we hear about with bog bodies, which are like the mummified people that are found in peat bogs, are in Europe because that's where the temperatures get cold enough. enough. So like below four degrees Celsius or below 40 degrees Fahrenheit, that limits bacterial spread in addition to just like slowing down chemical processes. But I think there are peat bogs that are closer to the equator too. So they're wet. Is the body wet when it's in the peat bog? Yeah. So it's a little bit more complicated than that. So part of it is the

cold temperature. Part of it is the lack of oxygen loving bacteria. So part of it is the cold temperature. Part of it is the lack of oxygen-loving bacteria. But part of it is also as the peat continues to decompose and rot, it releases natural chemical compounds collectively called bog acids or humic acids, which have really low pH levels. So they're really acidic. And acids slow down the decaying process by, I think, deactivating enzyme responses in your cells. So like in the way that you will pickle a cucumber in vinegar, the peat bog acts as kind of like an acid that you can pickle mammalian flesh in. Is it basically the same exact thing with different chemicals involved? Yeah, I think so.

So it also depends on what kind of plants are there. So in one article I was reading, sphagnum moss apparently releases a carbohydrate called sphagnum, which also extracts calcium. there are these bog bodies that people pull out that basically look like like in a cartoon where you like shake a body and then the skeleton flies out and then you're left with like a sack of a skin uh-huh that is what's left in the peat bogs because this compound from sphagnum moss dissolves everyone's bones in the peat bog i gotta admit i thought it was boring until you said the bone dissolving thing. I guess the butter is the less interesting one, but... The melting bones is really where you're going to hook people, I think.

I don't think other people think the bog butter is as funny as you do. Yeah, I think I get grossed out by the bodies, the idea of human corpses getting hollowed out. But butter is just so harmless. At Mandy Chu asks, who first realized a laser directed into people's eyes could correct vision and how? That's a really good question because it seems like a very bad idea to even try to do.

Well, I hate to break it to you that the idea starts out even worse. The idea didn't start with lasers. The idea started as how can we reshape the part of your eye that isn't working very good to focus light, to make it better at focusing light. And to do that, I'm going to explain eye anatomy. Do you know what your eye looks like?

What parts of your eye? Uh-huh. Lens, retina, the hole, whatever the hole is called. Pupil. The pupil. Yeah. The thing in the back of the eye uh-huh lens retina the hole whatever the hole is called the pupil the thing in the back of the eye that the that's the retina yeah oh darn i already said that one okay so if you think of your eyes like a sandwich uh-huh the top bread is your cornea it's what's in front of your eye it protects it from like scratches but it also helps focus the light and then next is your iris which is the part that contracts and expands it's the colored part and it has the pupil in the middle what is the parts of the sandwich you're not even saying

okay okay the top the top bread is the cornea keeps your sandwich safe and sound then you have the iris which is like a piece of ham in your sandwich but it has like a hole in the middle it's a bagel sandwich can i retcon this it's a bagel sandwich yeah yeah that makes way more sense it's a bagel sandwich there's a hole through the whole thing um pretend that the cornea protects that hole a little bit so like the top bun the hole isn't very big. It's got saran wrap on it. It's got saran wrap on it. Yeah.

Okay. We're getting somewhere. So the cornea is a saran wrap. The top bread of your bagel with the hole in it is your iris. Perfect. And the pole is the pupil. Yes. Then beneath that, you've got the lens.

That's your piece of ham, which is maybe kind of translucent. So like light can pass through it as well. Very thinly sliced. Very just paper thin honey ham. And then that light hits the bottom bread, which is. Not a bagel. Not a bagel. Solid.

Very sensory. What's the most sensitive bread? Oh, a marbled rye. Okay. It's a marbled rye then, because that's your retina. And that's where all the cones and rods and receptors are that receive the light and then transmit it through the optic nerve to your brain. So imagine there's like an electrical cable plugged into the bottom of your sandwich and that goes into your brain.

Yep. Okay. This is why Hank has the big science metaphors. We got to the bottom of that one. We did. Yeah. So in our saran wrapped bagel world, because the lens is kind of hard to get to, like you'd have to surgically go under a couple of layers. Eye doctors looked

at the saran wrap on top, your cornea, and said, okay, that is way easier to reach. So let us figure out ways to cut it or shave it off or alter it in some way to change how it focuses light and correct people's vision. In 1948, a doctor named Jose Barquer-Moner. I'm nervous about this because they don't have lasers in 1948, do they? No, they don't. Okay. He came up with a process called keratomeliosis, which comes from the Greek words for cornea and carve.

Uh-oh. And it's kind of like the worst possible way you could imagine this, but safe. You remove the cornea from the eye. You flash freeze it so it doesn't get all mushy and messed up. Okay. Then you reshape it with something called a cryolabe, which is just like a very cold knife, I think. And then you reinsert it into the eye. So that was like the first eye surgery. It was like,

okay, we've got to like freeze it, do it really fast, but really precisely reshape your cornea, stick it back in the eye. Then there were also non-freezing related techniques that developed in parallel. So a Russian eye surgeon named Slava Fyodorov worked on something called radial keratotomy in the early 1980s to help correct nearsightedness. And so if you imagine your eye bagel, it's like you cut from the center to the outside, like little spokes on a wheel or just with like a very clean, very sharp scalpel to reduce the focusing power and like flatten the cornea a little bit to basically like change how it focuses. They're slicing like a pizza? Yeah, yeah.

They sliced the cornea like a pizza. But then in the late 1980s, they got a little bit more advanced and figured out ways to do this operation inside the eye. So in situ keratomeliosis, which is basically taking off a small sliver of the cornea and then slurping out some of the stromal tissue underneath the top layer and then sealing it back up. And then in the 1990s, the first LASIK procedure was performed. And I never thought about what LASIK stands for, but it's just laser in situ keratomileusis. So they just tacked laser onto the front of the procedures they've been working on this whole time. And instead of using like a scalpel or a cryo lathe or any sort of knife, they used a laser because it was more precise cuts. It was like less invasive and it could cover

more types of refraction problems. Like it can make more precise cuts in more different ways to reshape the cornea. And so the basic process is still the same where they like peel back the top layer and then destroy some of the stroma to reshape the cornea and then plop it back down,

heal it up. But LASIK has progressed so much that like healing is really consistent and fairly painless and like the results are really consistently good because you're not like scrambling to shave off layers of a cornea while it's on ice. This was a weird question because I never thought of it. I don't wear glasses or do anything with vision, but there's a lot that went into eye surgery and a lot of people who are more comfortable poking around eyes than I ever would be. They didn't necessarily realize a laser could help people's eyes. They just did horrible things to people's eyes for 50 years.

I don't know if horrible. They corrected people's vision. They made it so people didn't have to wear glasses. Sometimes I bet there were loss of vision consequences. How about gruesome? Can we agree on gruesome? Okay. Not horrible. You're right. We got to be fair. We'll be back with one of your questions.

Sociology Notes asks, Why do spiders generally have eight eyes and eight legs? What are they all for? So spiders do have eight eyes. That's a fact. But generally speaking, they have two big primary eyes that function not so differently from our eyes. And the more I read about them, the more it seemed like maybe they see like the same way that we do, except they can see more of the visible, like the invisible spectrum or like light that is invisible

to us. They can probably see depth, color, ultraviolet light, and like all the good stuff that they need to be killing machines and do their killing. But then they have the smaller eyes that are usually like ringed around their primary eyes or lined up on their backs of their heads or whatever. And these are more attuned to changes in light and movement than they are like full proper eyes. And they probably don't provide as clear a picture or see color or anything like that. But spiders use these eyes to basically have super peripheral vision to either warn them that they're about to get snuck up on or help them identify prey. One source I was reading said that in insects, compound eyes behave kind of similarly, where it's like one big eye with a bunch of

different lenses and some of them are specialized to do different things so some can pick up some kind of lights and some pick up some kind of shadows things like that so instead of having one big compound eye for whatever reason they decided to have a bunch of other eyes to do all those jobs for them just like individual eyes but then also in one thing i was reading it said that spiders can't turn their heads. So that probably just helped for them to grow like light sensitive things on different parts of their bodies. And they just kept doing it because it was working for them. Because I think that's how evolution works, right? Yeah.

They weren't getting eaten as much. So they kept doing that. Then the eight legs thing, it seems to be even more than the eyes just because they do. They just have eight legs because that's what they ended up with. They don't need them all to climb walls or anything because I think right now scientists think that there's like little sticky hairs on the end of their legs that help them climb walls. It's not like they're like latching on having eight legs because a lot of research has shown that spiders missing up to two legs can do basically just as well as spiders with all eight of their legs. So they've looked at webs by six leg spiders and they look just the same as a web by an eight legged spider.

And they're not any worse at hunting than an eight legged spider is. And then after losing two legs, it kind of starts to mess them up. And maybe had more than eight legs some people think too and that two of their legs turned into their creepy little mouth parts that they have i was gonna ask maybe they have 10 legs sort of but the eight legs eight eyes thing i think is just a delightful coincidence at andrew tops asks is it possible that we could get rid of a disease like for good or have we already done it how is it possible that we could get rid of a disease like for good? Or have we already done it? How is it possible or impossible? Have you heard of any diseases that we've eliminated? Do you know?

Polio? Did we get rid of polio? I don't think so. Not in this way. So like it would have to be a virus or something. And we'd have to get rid of every single one of them. That's like one definition of what's called disease eradication is like getting rid of everything that causes a particular disease. So like all the viruses, all the bacteria.

And if you go by that definition, we haven't gotten rid of anything for good. But there's another definition of disease eradication that's basically intentionally stopping infection from a disease worldwide permanently. And two diseases fit that definition. Basically, it's like we've stopped infection. They're not going to infect anyone else. But some scientists have samples in their labs and aren't going to destroy them. If they were floating around in the world, would they make people sick? Yes. Okay. So it's not like we've vaccinated everybody against them or something it's no we've captured them and they're in jail

yeah they're in they're in like max prison so one of them is smallpox um which we do have a vaccine against and you've probably heard about it's it's i feel like in my brain in the same category of polio of like viruses that were huge epidemics within the last couple centuries. And smallpox is specifically the one that causes a big red rash and also severe flu-like symptoms. And it's caused by the variola virus. The last reported case of smallpox was in Somalia in 1977. And it was officially declared eradicated by health officials in 1980. And now there's only samples of it stored in the United States and Russia. On the CDC's website, it says

there is still smallpox research in the United States to focus on vaccines, drugs, and diagnostic tests in case anyone gets their hands on it or recreates smallpox and turns it into a bioweapon. But it's not possible that it's like in some animal or something somewhere. Like, we're pretty sure it's not just floating around out in the world anymore. Yeah, I think that's what that gap between the last observed case and the officially declared eradicated was was like probably some research into okay everywhere that still had strains of the virus is it there is it anywhere that we can detect it would need to have incubated in people in this amount of time for it to still be around or something like that okay and so safely declared

that eradicated but that's the only one in humans that is gone. There's like a next classification called disease elimination, which is not worldwide, but reducing cases to zero and like stopping infection in a defined geographic area. So like the example that they gave on this website was elimination of cholera from countries like Peru, but the cholera bacteria is still in other countries and like still causing infection there. So it's like eliminated, but not eradicated because I think we were getting too demoralized by only eradicating one human disease. So we had to come up with some new benchmarks or something? Yeah, lower benchmarks. But then the second one that's been eradicated is a disease called rinderpest. That sounds bad.

Yeah, it's a cow disease. They have like a mix of a fever and diarrhea, also kind of like flu symptoms and just like a lot of like discharge. It's a very like goopy disease. lot of like discharge it's a very like goopy disease so it spreads through cattle populations really quickly and it doesn't affect humans but we just rely on cattle for so much for like farm labor and food and milk so it was just like devastating to local economies particularly ones that use cattle and that was like a really big global effort to eradicate this disease. And so a vaccine was made and distributed. When did that happen? The last reported case of Rinderpest occurred in Kenya in 2001, and it was declared eradicated in 2011. So pretty recently. And that has more samples scattered in labs around the world, I think because it was such a collaborative effort to make vaccines and to study it and get rid of it in more recent years, there are a lot of labs

that still have small samples of it or small samples of the vaccine. And so some health officials, the Food and Agriculture Organization of the United Nations and the World Organization for Animal Health are two organizations that are asking labs to basically decide where they want to keep if they want to keep any samples of rinderpest and store them in that and destroy everything else because they don't like that there's so much out there. Would you even need to keep that or is that one we could get rid of all of? It's like a complicated question that I don't really know enough about. Humans and scientists particularly like to store things. It's like, well, just in case.

I don't know how active the smallpox research is. And like rinderpest will probably be even less active research. But they're just like, well, in case like a mutated strain comes back, we should have it. Or I don't know, governments are just like protective of information that they have. So we could hypothetically throw smallpox in an incinerator and it would be eradicated. Yep. Yeah, I think so. But we've decided not to. Do you have any thoughts on how it is possible? How do they do it? I don't know. That seems like the most impossible thing to me. Just like figuring out how pretty good idea of what is transmitting it. So like whether it's like in dirty water. So like in the case of a lot of cholera, it's like sewage systems or plumbing systems that are like the systems at fault. And so we like

start by narrowing down how the disease is caused, what systems can be failing people public health wise so that they can get the disease, and then how we want to tackle helping that. And this is pure speculation, but my guess is that because smallpox is something that affected Europe and America, there's probably more active effort to be like, let's track down every single person who has this and like isolate them and vaccinate our children and do everything widespread. And we already sort of had the like the infrastructure to do that, to be like, when this baby comes out, it is going to get a smallpox vaccine as like part of this routine checkup. But other diseases like malaria or something, even though there is research and

money going into it, there's less of that that panicked urgency. And so you hear about organizations finding ways to genetically modify mosquitoes or to find out better ways to diagnose the disease, but it might be harder to come up with public health efforts that are working with the communities that are most susceptible to these diseases to like eliminate them like like if there's a community that isn't used to getting vaccinated to like convince everyone to get vaccinated is a different task and like requires a lot of local outreach and things like that i don't know i don't want to like speak over public health experts but i think that's where it gets tricky, where it's like when people start swooping in to other cultures to be like, we will fix your health. I think there are a lot of challenges there that are different than, oh, no, people in our country are dying. We're going to throw a bunch of money into fixing this. If you want to ask the Science Couch your question and either have it answered a couple weeks after you ask it or years after you ask it, follow us on Twitter at SciShowTangents

where we'll tweet out topics for upcoming episodes every week. Thank you to at Sneffin, at Kobamanser, and everybody else who tweeted us your questions for this and every episode. We couldn't do it without you and all of your great questions. Thank you. Yeah, it's fun to answer them. I learn a lot from hearing what other people ask. And it is interesting for me to learn what I've been desensitized to as interesting information because I've been working in science communication for five years now. Yeah, it's fun to read questions that you didn't know that you'd never thought of before and then all you can think about all day is how the hell somebody shot a laser into an eye and then the real answer is more interesting than somebody just shot a laser into an eye if you like the show and want to help

us out it's real easy to do that first leave us a review wherever you listen it's super helpful and it helps us know what you think about the show second tweet out your favorite moment from this episode and finally if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I have been Sam Schultz. And I've been Sari Reilly. And that's it. That's it. Yeah, it's just the two of us. And Tuna. Silent partner Tuna. He's waving to all of you right now and saying something. Hi, hi.

SciShow Tangents is created by all of us and produced by caitlin hoffmeister and me i also edit a lot of these episodes along with hiroko matsushima our social media organizer is paola garcia prieto our editorial assistant is the boki chakrabarti our sound design is by joseph tuna medish and we couldn't make any of this without our patrons on patreon thank you and remember the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. There is an article published on June 29th, 1922 in the journal Proceedings of the Royal Society of Medicine entitled Specimen of a Miner's Egg, in which a doctor describes how a Chilean silver miner tried to smuggle a chunk of silver ore by coating it in candle wax, sticking it up his butt, and pooping it out later like a chicken laying an egg.

However... It must not have worked, I guess. Yeah, however is key. This 4 inch by 2.5 inch by 2.5 inch egg was too big to be squeezed back out of the butthole. In fact, the doctor wrote, quote, when gazing on this large specimen,

it is hard to believe that any human being could have thrust it through his own sphincter muscle, yet the feat was actually performed, end quote. So it had to be surgically removed and ended up in a museum. So the miner didn't even get his silver that he smuggled out. It ended up in a museum of what? Like I think of weird surgery. Oh, cool. The article is quite good. We'll link it in the show notes. It's so short, but so hilarious. Like he comments on the wax of it and said it was marked on the outside by moldings of the rectal mucus membrane. Because the butt was really clenching around that wax egg thing.

And like it's implied that this was a common way. Or not common, but like if you wanted to smuggle silver out implied that this was a common way or not common but like if you wanted to smuggle silver out like this is a thing and he just chose too big of a piece of silver his eyes were too big for his butt yeah